GM2Godot

Inspiration

I self published two games on Steam under the GameMaker engine in 2022 and 2024, The Colorful Creature and Asteroids ++. After publishing those, I have moved to Godot for my third project, but I had to maintain the older games to keep players interested. But it was a hassle to deal with an older engine which didn’t have a simplier way to make CI/CD pipelines, no built in input system, etc

Then I decided to make an open source tool, which at first was just porting assets from one engine to another, and now transpiling the GML language to GDScript

What it does

The tool brings all of the game assets and code from GameMaker to Godot, and the conversion process is very fast, modular, and easy to use. Import the gamemaker project, then the path of the empty godot project, and run the conversion. The app will bring config files and settings, game title, icon, description, audio buses, sprites, music, sounds, and transpile GML code to GDScript, a language that Godot can understand

How we built it

I built it using Codex with GPT-5 series models in Python

Challenges we ran into

Understanding both engines is very difficult. Both engines are different, but because of Godot’s open source nature, it’s an easier process to transpile to Godot (and more useful) than GameMaker. This involved a process looking through the structure of both engines, and their documentation, and the app needs to ensure that compatibility exists so that an old gamemaker version can successfully pass the conversion to Godot.

Accomplishments that we're proud of

The fact that very simple games work out of the box. It’s possible to convert games such as top down shooter games, games like pacman, which were entirely made from GameMaker, and then GM2Godot can transpile it to Godot

What we learned

Multithreading process of dealing with thousands of files. Python is slow in nature, but coding it right will produce good results.

And CI/CD took a large part of the project, where a newly added feature must have its unit test, in case that the app incorrectly transpiles the code to Godot.

What's next for GM2Godot

I want to introduce a brand new mode: ‘Deep Mode’, which will after the standard conversion use AI agents to analyze files and fix/clean up code that is broken or bloated.

Because GM2Godot transpiles languages, it creates helpers which may not be needed for all projects. I’m hoping for deep mode to be able to research all relevant files in the project, seek connected files and classes and then produce a more favorable result. I plan using free providers to achieve this method for users who want to use it on their system, likely OpenCode agents, or even being able to use Codex agents.

Built With

• codex
• gdscript
• gml
• python